DE1950667A1 - Electric capacitor - Google Patents

Description

The invention relates to electrical capacitors and, more particularly, to those having an electrode, which is designed as a foil electrode, while the other electrode consists of a metallized strip whose 'metallization takes up the entire strip width. A metallized electrode for a wound capacitor can be used as a thin layer of electrode metal, such as aluminum, can be described, which is suitably applied to a. dielectric strip is applied, which consists e.g. of paper or resin material. Metallized electrodes are for suitable for use in various capacitors, in particular in load capacitors, because of their known electrical self-healing properties and since they reduce the overall volume of the capacitor. The metallization can

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be generated by various methods including Metallverdanipfung "that can be controlled so that particular permeability can be achieved with respect to a ¹ electric liquid impregnating agent. In a tightly rolled wound capacitor element, it is difficult to provide a full, complete or nearly complete impregnation inside ode .r in central parts of the coil, if the only dielectric used are originally non-porous resins, and if a resin film used in the dielectric medium also includes a metallized layer thereon as an electrode. -.- ^!

A special disadvantage when using metallized electrodes refers to uncoated or non-metallized To use edges on the metallized electrodes in order to avoid short circuits at the edges of the coil. These uncoated edges add significantly to the cost of the capacitor in, especially in the additional process steps, such as covering by masks' while at the same time no additional advantages in terms of the capacitor can be achieved.

Other disadvantages of using metallized electrodes are making sure that all leads from one Go out of the end of the capacitor and regarding capacitors, which are composed of many sections, this consists Problem of performing the separation of a strip made of a metallized material in the longitudinal direction or the metallization to produce a pair of electrodes with a common electrode. When separating a metallized Strip the dielectric strip is also separated, so that further isolation is necessary at this point or further procedures must follow in order to remove a part to remove the metallized layer.

To avoid the disadvantages indicated, according to the invention

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Proposal proposed to use a dielectric strip in a combined capacitor, which has a metallized Has a layer of aluminum that extends over the entire width of the strip. In connection with the metallized strip a self-supporting metal foil strip is provided, which has a smaller width than the dielectric strip, and by a further dielectric strip which is wider than the foil strip from the metallized one Strip that is spatially separated. The layer arrangement described is rolled up in a spiral shape and can be used as a Dry condenser or as an impregnated condenser in a suitable housing.

The invention is explained in more detail with reference to the drawing. Show here;

Figure 1 is a view of a preferred embodiment of the invention a combined capacitor;

Figure 2 shows a partial cross-section from Figure 1, the individual self-supporting strips for the purpose of clear Representation are arranged separately;

FIG. 3 shows a partial cross section similar to that of FIG. 2;

Figure 'I a rolled up capacitor winding with an.

Conclusions and
FIG. 5 shows an assembled capacitor located in a 1ef-3.

In Figure 1 is an example Ausführungsforr. of the invention in the form of a wound capacitor section 1 "- which is often referred to as a combined or mixed electrode capacitor.

A combined or mixed electrode capacitor comprises an electrode of a discrete s e Ib s-tt rarer

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BAi ORIGINAL

1950657

the electrode structure j such as, for example, an aluminum-metal foil and another different electrode which is normally provided with a metal layer or which is made by metallizing a suitable dielectric material. In between there is a separate dielectric Stripes. A combined capacitor can also have mixed dielectric strips, one of one synthetic resin - material that can be metallized is and the other strip of a paper-like Material can exist. In dry capacitors, the dielectric materials "are usually the same. In impregnated Capacitors can be more highly absorptive or porous Material can be used for the other dielectric material.

A preferred arrangement of a combined capacitor is shown in FIG. 1 as a winding section 10. The section 10 comprises a first dielectric strip 11, which consists of consists of a dielectric strip material known per se, the paper and 'such synthetic resins as polyethylene, Terephthalate, polysulfone and preferably the. Polyolefins in particular includes polypropylene. The strip 11 is on one Surface with a layer 12 of a suitable electrode material such as copper, zinc or aluminum covered or coated. The metal layer 12 preferably consists of one metallized aluminum layer with the ^ dielectric Strip 11 is integrally connected for reasons of retention, the can be produced by metal evaporation processes known per se.

In this invention the metallized layer extends to the maximum width of the strip 11, or in other words, the layer 12 coincides with the V, ^T side of the strip 11 so that the strip 11 is, for all practical purposes, a borderless strip .

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The non-metallized side of the dielectric strip 11 Next adjacent is a free or self-supporting aluminum foil strip 13 as the opposite electrode arranged to the aluminum layer 12. The aluminum foil strip 13 is, since it represents an integral foil strip, narrower than the strip 11, so that it can thereby be overlapped on both longitudinal edges. .

Next to the aluminum foil strip 13 is a dielectric strip I ¹ I, which can be made of a resin material or, for an impregnated capacitor, of a porous material such as Kraft paper or any other similar material, which has higher absorption properties than the generally used dielectric liquid Impregnating agents such as mineral oil, storage oil, silicone oil, cottonseed oil and the chlorinated hydrocarbons such as trichlorodiphenyl. In this invention, the length of the dielectric strip I ¹ I is at least equal to that of the strip 11 for practical reasons.

When assembling the winding portion 10, one or more dielectric strips 14 as well as one or more Resin strips 11 can be used, only the outermost strip having a metal layer 12 thereon. When winding up " of the section 10 with the dielectric strip 14 as the center of the revolution results in a cross section of the winding of the of Figure 2 © nt-gp ^ e ^, with the self-supporting strips are shown in an expanded arrangement. With regard to Figure 2, it is particularly noted, that between a pair of electrodes, such as the metallized electrode 12 and a foil electrode 13 only one of the dielectric strips 11 or 14 is arranged, and that the other dielectric strips between the electrode 13 'and the next turn of the opposite electrode 12, which is denoted by 12 ', is located. However, if the dielectric strip l4 made of a different material, such as

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Then the foil electrode 13 inside the roll has a more easily impregnable paper strip IA on one side, while on the other side there is the difficult-to-impregnate resin strip 11. The dielectric strip 11, however, is covered with a metallized layer which can be impregnated in a predetermined manner by a dielectric liquid impregnating agent j or which is provided with suitable pore openings or other means for admitting the liquid produced at one end of WickeIs for the purpose of a metal coating or a ■ metal spraying method according to Schoop a supernatant metallized edge, and through the paper at the other end of the coil for the purpose of Metallgefaßisolation _y made the wrapping section for impregnation placed in a metal vessel

In a combination capacitor is a self-supporting one or foil electrode advantageous, as it is more economical, than metallized strips, has a higher thermal conductivity; a strip connection is easy to manufacture and is suitable for a multiple division can easily be separated. An example a multi-section capacitor is shown in U.S. Patent 3,365,632 to Framame.

An important feature of the invention is that the metallized layer 12 on the dielectric strip extends over the entire majority of the strip 11 and that none uncoated edges need to be present on the strip 11 '. It is common in the manufacture of metallized film electrodes common - uncoated edges or borders on the Provide dielectric to be metallized, e.g., from U.S. Patent 3,292 Οβί to Eustänce.

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Such edges are necessary to avoid short circuits between the metallized layer / to prevent the winding edges. E.g. has a pair of dielectric strips, each having a metallized surface, and in a capacitor winding section is rolled up, on the winding edges metallized surfaces in a critical electrical short-circuit relationship. However, by using an intervening dielectric strip, as shown in Figure 2, the short circuit problem is reduced and a rimless metallized electrode can be used. It's a special one Advantage of the present invention that the uneconomical feature of the edges is avoided because of adjacent electrodes in a "capacitor winding" either by a strip of paper or by a strip of resin from an adjacent electrode are separated and the width of the present electrode can be can be produced more conveniently and faster than that of the metallized layer. This elimination becomes an important one Advantage, namely an increase in the capacity of the winding section because of the larger electrode area and achieved also an even greater reduction in capacitor volume than with metallized edge electrodes.

As shown in Figure 2, the metallized .Schicht isolated from the electrode 13 by using a dielectric strip 1 * 4 therebetween. The metallized Layer 12, in conjunction with its strip 11, extends beyond strip 14 on the right-hand part of the roll so that the metallized layer 12 is exposed at this Viickelkante and in Conventionally with a .Metall can be applied or coated by the Schoop method, in order to have an electrode thereon to fix. The metallized layer 12 is from the foil 13 through the electrical strip 11 on one side and through the dielectric strip 14 on the other side isolated. By offsetting the dielectric strip 14 between layer 12 'and electrode 13' and by the fact that the film 13 is narrower than the strip "14" actually isolates layer 12 from electrode 13. V.'erm

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the electrode 13 by chance on the surface of the dielectric Strip 14 has a metallic layer, an uncoated edge on the strip 14 is necessary. Since the Electrode 13 is narrower than strip 14 j. becomes the possibility almost eliminated that the spray-on or the Schoop method makes a metal contact with the foil 13.

In the case of metallized capacitors, it is particularly advantageous if the connections protrude from one end, which is particularly important is important for load capacitors. Because of the edges, however and the convenience-of the opposite edges in the Wrapping edges have metallized capacitors a connection, that protrudes from each end. Usually a suitable metal over each end of the capacitor winding section sprayed or piled up where a metallized edge is exposed and a terminal is connected to that sprayed metal. One such method is, for example See U.S. Patent 3,256,472 to Centurioni and described. However, as has already been said, it is the case with load capacitors and especially with capacitors that consist of several Sections consist, for example, of the US Patent 3 3 ^ 5 632 by Grahame, particularly advantageous, when all connections protrude from one end.

In the present invention, the metal spray or Schoop procedures for all connections with the exception of the common capacitor connection are avoided because they are not common Terminals protrude from the foil electrode 13, which can be assembled as an ordinary strip connection. For example, as shown in Figure 1, a suitable strip tape or wire feed is 16 with a small square attached to an aluminum foil 17, which in the folgerf ^ uls '' flag " referred to as. While the roll is being rolled up, the "flag strip" (16 and 17) is placed in the desired position Position used as the electrode feed for the electrode foil 13 serves. The feed for the aluminum layer 12 can be produced in the generally customary manner, as in FIG U.S. Patent 3,256,472, -or it may be by

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other suitable connection methods for leads usable for metallic films are produced, and although on the opposite or the same end of the Condenser from which the feed 16 starts.

The special structure and the arrangement of three feeders, which e.g. from the same end of a capacitor, which from many Sections consists, protrudes, is shown in Figures 3 and more clearly.

In Figure 3 is a capacitor section 18 with various self-supporting strips in one for the purpose of a distinct Representation of separate arrangement shown. The dielectric strip 14 and the foil electrode 13 are offset from one another with respect to the resin strip 11 and the aluminum layer 12 located thereon. The electrode foil 13 is next adjacent a strip 16, as shown in Figure 1, is arranged. The strip 16 can directly, with the aluminum foil 13 attached by welding, clamping or the like or can be used in conjunction with a "flag element" 17 for frictional adhesion in the wrap. To for to provide suitable electrical connections to the aluminum layer 12 as well as to the electrode 13 when the section 18 in ■ a winding form is rolled up, an insulation 19 can be on a portion of the strip tape 16 may be provided in order to isolate the strip 16 from the protruding aluminum layer 12. The strip tape 16, however, does not need to come into contact with the aluminum layer 12 because of the burn-off (self-healing) the metallized layer to always be short-circuited, so that the insulating layer 19 after. Choice can be provided.

Figure 4 shows the connections of the winding part more clearly, when the portion 18 of Figure 3 is rolled up into a winding form. In Figure 4, the winding part 21 illustrates the Winding shape of the part 18 according to Figure 3. At one end of the

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Winding part 21 according to Figure H ist.ein connection 22 to the aluminum layer 12 produced by the aforementioned metal spraying process or the Schoop process. A metal layer 23 applied according to the Schoopy process is provided over half a part of the coil and the feed 22 is connected to it by welding, soldering or other suitable fastening methods. As shown in Figure 2, the metallized layer 12 extends a little beyond the paper strip 13 at one end of the roll, so that it is exposed at the roll edge for a Schoop process. The dielectric strip 14 extends beyond the winding edge (determined by strip 11) at the other end of the winding section for the purpose of tape insulation if a tape is used at this end. By leaving part of the end 21 unsprayed with any molten metal, such as metal 23, one-piece strips 16 can be drawn out of the coil, as shown in FIG.

This invention therefore includes, in one embodiment, one first dielectric material strip e.g. a resin strip 11, spaced from a second strip of dielectric material such as another strip of resin 14. For example, polypropylene and polysulfone are resins for each of strips 11 and 14. Between these dielectric strips is a film strip such as strip 13j of the second dielectric strip 14 is adjacent, which completes the arrangement.

Reference is again made to FIG. 2, in which the film strip 13 can be replaced by a dielectric strip which is porous or non-porous, or made of paper or resin, that is metallized on both sides (double metallization) and which is given a structure that is self-supporting. The double metallized dielectric material is made preferably made of paper. The dielectric strip 14 can consist of a composite shape or a sandwich structure, for example a pair of strips of paper

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and an intermediate strip of resin. The resin strip 11 can also be made of a composite shape, for example made of a pair of resin strips and one in between

Consist of paper strips. ·

The invention as illustrated in Figure 1 is capable of a number of other modifications. For example, the foil electrode '13 does not need to be between the paper strip 14 and the resin strip, but can be located on the inside of the roll so that, viewed from the inside out, a foil-paper-metal layer is arranged in comparison to FIG. that the paper layer I ¹ I, the film 13 and the resin 11 comprises. In any case, the roll can be rolled up with the film strip 13 as the inside or outside strip of the roll or with the paper strip Ik as the inside or outside strip of the roll.

The film strip 13 can additionally and - where applicable - be replaced in favor of a metallized layer on the adjacent paper strip. The electrodes 12 and 13 can be replaced by other electrode arrangements. As an example, foil electrode 13 can be replaced by a metallized strip which is metallized on one or both sides, ie by a double-metallized paper strip, which strip may or may not be porous. ¹ from the same reason, the layer 12 may include a separate metallized strips.

In all embodiments of the invention, one or more the strips 11,12,13 and I ^ through an integral sandwich structure, as described, for example, in U.S. Patent 3,363-15-6, be replaced.

The invention can preferably be used as a dry or non-impregnated capacitor and can also be used with an impregnated capacitor containing such dielectric liquid impregnating agents as mineral oil,

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Cotton seed oil, storage oil, silicone oil and halogenated hydrocarbons, especially trichlorodiphenyl, are used.

The embodiment according to FIG. 4, for example, can be more advantageous _{in t.} Can be used as an impregnated capacitor if a suitable vessel or housing is provided, as can be seen in FIG.

The injFigur 5 shown capacitor 24 comprises a vessel 25, a capacitor winding section such as section 10 and according to Figure 1 and 4 houses. When assembling the capacitor 24, a winding section such as the winding 10 according to the figure is first flattened into an oval shape. Then the Schoopschicht 23 and the connection 22 are attached and the arrangement is fitted into the vessel 25. Both connections-Ϊ6 --- and 22 are internal connected to the connections 26, 27 and 28 on the vessel 25. The vessel 25 contains the dielectric liquid and is therefore sealed for these purposes.

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Claims (11)

Expectations "■. Electrical wound capacitor consisting of a pair spaced dielectric strips with alternating electrodes therebetween, thereby marked that one of the electrodes (13) has a self-supporting strip structure, while the other electrode has a metallized layer (12) on one side has one of the dielectric strips (11) carried thereby and that the metallized layer (12) with the Much of the supporting dielectric strip (11) is almost matches. .. 2. Capacitor according to claim 1, d a d u r c h characterized in that the winding with a dielectric .The liquid is impregnated. . 3. Capacitor according to claim 1 or 2, characterized in that one of the dielectric Strip made of paper. 4. Capacitor according to claim 1 or 2, d a 'through ge ken η draw t that each of the dielectric Strip made of paper. 5. Capacitor according to claim 1 or 2, characterized marked that at least one of the dielectric strips is made of synthetic resin. 6. Capacitor according to claim 1 or 2, characterized ' characterized in that each dielectric strip made of synthetic resin. 7. Capacitor according to claim 5 or 6, characterized characterized in that the resin comprises polypropylene. 009818/1222 8. Capacitor according to claims 1 - J _3, characterized in that the self-supporting electrode (13) is separated in the longitudinal direction in order to create a capacitor with many sections. 9. Capacitor according to claims 1-8, d a du r c h ge know that the self-sustaining Electrode consists of a double-metallized porous strip. ; 10. Capacitor according to claim 1 or 2, d a d u r c h known that the self-sustaining Electrode (13) from a foil strip electrode of a specific Width consists in that a further overlapping paper strip dielectric (14) is arranged adjacent to it, that a metallized strip electrode of a certain width, which is wider than that of the Polienelectrode strip (13) is, a metallized surface (12) adjacent to the paper strip dielectric (11) has that a metal layer (23) is provided on one end of the roll to provide a feed (22) to the metallized strip to create and that a strip tape (16) is connected to the film strip and extends from one end of the roll. 11. Capacitor according to claim 10, d a d u r c h g e k e η η ζ- e "i c h η e t that the metallized strip of paper or made of synthetic resin. 009818/122 2